Electrical ageing markers for polyethylene insulation based on space charge accumulation and apparent mobility

Space charge accumulation within polymeric materials has been associated with their accelerated ageing. The measurement of this phenomenon can be used to correlate space charge profiles and their evolution to ageing. In this paper, accumulated charge depletion after long electrical ageing processes has been analyzed following a research trend pointed out in previous works. In order to extend this analysis to several materials, the electrically barely known UHMWPE (Ultra-high molecular-weight polyethylene), mostly used in medical applications, has been compared to well-known XLPE and LDPE. It has been proposed some extremely simple indicators that can be used to know the ageing of a polymeric insulation without incurring in simplifying assumptions and using only the charge profiles obtained directly from the space charge measurements taken by PEA (Pulse Electro Acoustic) method.